Correspondence, letterbooks, diaries, journal, military papers, financial papers, scrapbooks, and other papers relating chiefly to Dewey's activities as naval commander in the Far East during the Spanish-American War, especially at the battle of Manila Bay; as admiral and president of the U.S. Navy General Board (1899-1917); as president of the court of inquiry (1901) concerning Winfield Scott Schley; and as commander-in-chief of naval winter maneuvers (1902-1903). Also includes Dewey's letters to his second wife, Mildred McLean Hazen Dewey, her correspondence, financial records, and papers pertaining to her estate; correspondence between Dewey's parents, Julius Y. Dewey and Mary Perrin Dewey; letters from James A. Garfield and William T. Sherman to Mildred Dewey's first husband, William Babcock Hazen; and an account (1904) of Admiral Dewey and the Manila campaign written by Commander Nathan Sargent, U.S.N.

George Dewey's correspondents include Charles J. Bonaparte, William E. Chandler, George B. Cortelyou, George Creel, Josephus Daniels, Grenville Mellen Dodge, John Hay, Robert Lansing, John Davis Long, A.T. Mahan, William H. Moody, Paul Morton, Truman Handy Newberry, Redfield Procter, Theodore Roosevelt, Elihu Root, and Oscar Fitzalan Williams. Mildred Dewey's correspondents include Frederick M. Bugher, Jonathan Daniels, George G. Dewey, Henry Cabot Lodge, John R. McLean, Elisabeth Ellicott Poe, and Alvin Untermyer.